The Clinical Core recruits and longitudinally assesses patients with various dementias, including those with dementia of the Alzheimer type (DAT), for comparison with control subjects on clinical, behavioral, and biomedical measures. In doing so, Core data are collected, archived, and analyzed through interaction with the Biostatistics Core and are integrated with data from the Psychometrics Core and the Neuropathology/Tissue Resource Core. The Core provides DAT patients and controls for the Molecular Genetics of Dementia project and the Processing Speed and Working Memory in DAT; and Pilot 12.5 (Cognitive Deficits and Speech Perception in DAT project. The Core also supports affiliated projects not funded by the Alzheimer's Disease Research Center (ADRC), including the affiliated submitted RO-1 application, "Cognitive Change in Cerebrovascular Disease". The Core additionally acts to promote broader research efforts outside of our institution through participation in funded (e.g., Consortium to Establish a Registry for Alzheimer;s Disease, AG06790; Alzheimer's Disease Cooperative Study Unit, AG10483) and nonfunded research activities, including efforts to standardize the diagnosis and stage the severity of DAT, investigate issues of heterogeneity and to examine biologic markers for AD. These objectives remain consistent with the clinical theme on which our ADRC was established: the longitudinal characterization of the clinical features of DAT and related dementias and exploration of the relationships between healthy aging and mild dementia. To this end, the Core continues its commitment to clinicopathological correlative studies by obtaining autopsies in both controls and patients; current autopsy rate in decedents from the Patient Registry is 70%. These activities complement but are budgetarily and scientifically distinct from those of the Program Project, Healthy Aging and Senile Dementia (AG03991).